Compressed gas delivery system

ABSTRACT

A compressed gas delivery system includes a control system and at least one compressor fluidly connected to the control system for providing a compressed gas to the control system. The system also has a backpressure apparatus that is fluidly connected between the at least one compressor and the control system. The backpressure apparatus conveys a portion of the compressed gas to the control system. The compressed gas delivery system also includes a bypass conduit that is fluidly connected between the at least one compressor and the backpressure apparatus. The bypass conduit conveys a portion of the compressed gas through the flow limiting distributor directly to one or more vehicles during a dispensing operation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the filing benefit of U.S. Provisional PatentApplication No. 62/069,610, entitled “Compressed Gas Delivery System,”filed on Oct. 28, 2014, the disclosure of which is expresslyincorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to compressed gas distributionand, more particularly, to compressed gas distribution for continuouslyrefueling multiple vehicle tanks.

BACKGROUND OF THE INVENTION

Typical compressed gas systems for filling one or more vehicles arefast-fill, time-fill, or combination-fill. A fast-fill compressed gassystem dispenses compressed gas at a rate similar to what a user wouldexperience using a conventional gasoline or diesel system. To achievethis rate of fill, a fast-fill compressed gas system utilizes one ormore storage tanks and compressors to dispense compressed gas tovehicles. A time-fill compressed gas system is designed where a longerfueling window is available, typically overnight from 4 to 12 hours. Ina time-fill compressed gas system, vehicles are generally filleddirectly from one or more compressors, not from storage banks. Acombination-fill compressed gas system combines features of bothfast-fill and time-fill systems, thereby having the ability to fast-fillvehicles throughout the day and also time-fill vehicles overnight.

There are multiple types of fast-fill systems including cascadefast-fill systems and buffered fast-fill systems. Cascade fast-fillsystems are commonly used in retail applications and where vehiclesarrive randomly for refueling. Cascade fast-fill systems are designed tohave enough storage capacity to handle peak fuel demand with one or moreappropriately sized compressors to meet the fueling demand andadequately replenish the compressed gas storage over a given period.Unlike cascade fast-fill systems, buffered fast-fill systems dispensedirectly from the compressor into one or more vehicles and have asmaller quantity of storage. Buffered fast-fill systems are commonlyutilized for captive fleets for sequential fueling of high fuel usevehicles one after another, such as taxis and transit buses. The storageis designed to allow the compressors to operate while the vehicles arebeing interchanged.

In the United States, the industry standard pressure rating forcompressed natural gas for a user's vehicle tank is 3,600 psig at 70° F.While 3,600 psig at 70° F. is the target vehicle tank pressure, thiscould change significantly based on vehicle design and the region orcountry of operation. For example, some systems in the United States andother systems in other countries are only rated to 3,000 psig. Vehicletanks are typically designed to be filled to 125% of their ratedpressure. Thus, a 3,000 psig vehicle tank can be safely filled toapproximately 3,750 psig, while a 3,600 psig vehicle tank can safely befilled to approximately 4,500 psig. Most compressed gas systems wouldnot fill a 3,600 psig rated tank past approximately 4,100 psig, sincethe desired tank pressure is approximately 3,600 psig at 70° F.

A typical cascade fast-fill system has one or more compressors forcompressing gas and three storage banks: a low storage bank, a middlestorage bank, and a high storage bank. Outside the United States, acontrol system typically directs the flow of compressed gas from thelow, middle, and high storage banks to one or more compressed gasdispensers, while in the United States, one or more dispensers typicallydirect the flow of compressed gas from the low, middle, and high storagebanks to one or more vehicles located at the one or more compressed gasdispensers. A control system, commonly referred to as a “prioritypanel,” typically operates so that the low storage bank conveys astorage fill portion of compressed gas through the control system to avehicle tank. As used herein, the terminology “storage fill portion ofcompressed gas” is intended to describe that portion of the compressedgas from the one or more compressors that is either stored in one ormore of the storage banks or that portion of the compressed gas storedin one or more storage banks that is dispensed through the controlsystem to one or more vehicles. The control system or priority panel ordispenser operates so that the low storage bank terminates fill upon apredetermined characteristic, such as a minimally accepted flow rate ora substantially equalized pressure between the low storage bank and thevehicle tank. Minimally accepted flow rate could be utilized since asthe storage bank pressure and the vehicle tank pressure equalize, thepressure differential between the storage bank pressure and the vehicletank decreases, causing the flow rate to decrease. For example, the lowstorage bank may terminate fill at approximately 2,000 psig. However,this 2,000 psig value can significantly vary, as this pressure is highlydependent upon a number of variables including the tank pressure at fillinitialization, the pressure of the gas supply, and environmentalfactors.

After the control system or priority panel or dispenser terminates thefill from the low storage bank, the control system or dispenser thenoperates to convey a storage fill portion of compressed gas from themiddle storage bank, through the control system, and to the vehicle. Thecontrol system or the dispenser allows gas to flow from the middlestorage bank to terminate fill upon a predetermined characteristic, suchas minimally accepted flow rate or substantially equalized pressurebetween the middle storage bank and the vehicle tank. In thisembodiment, the middle storage bank may terminate fill at approximately3,000 psig. However, like the 2,000 psig termination of the low storagebank, this value can significantly vary, as it is dependent upon anumber of variables.

After the control system or priority panel or dispenser terminates thefill from the middle storage bank, the control system or dispenser thenoperates to convey a storage fill portion of compressed gas from thehigh storage bank, through the control system, and to the vehicle. Thecontrol system or dispenser then operates the high storage bank toterminate fill upon a predetermined characteristic, such as a minimallyaccepted flow rate or a substantially equalized pressure between thehigh storage bank and the vehicle tank. In this embodiment, the highstorage bank may terminate fill at approximately 3,400 psig, forexample. Like the 2,000 psig termination of the low storage bank and the3,000 psig termination of the middle storage bank, this value cansignificantly vary, as it is dependent upon a number of variables. Sincea full tank pressure is approximately 3,600 psig at 70° F., the vehicletank may then be directly filled. Direct fill means that a direct fillportion of the compressed gas is conveyed from at least one compressorthrough the control system or priority panel and directly to the vehiclebeing filled. The terminology “direct fill portion of compressed gas,”as used herein, is intended to describe that portion of the compressedgas from the one or more compressors that is not stored in any storagebank arrangement, but rather, is dispensed directly through the controlsystem to one or more vehicles.

A buffered fast-fill system utilizes a single storage bank. The storagebank could be a single storage tank or the storage bank could havemultiple storage tanks. The control system conveys a storage fillportion of compressed gas from the storage bank to the vehicle throughthe control system. The control system operates the storage bank toterminate fill upon a predetermined characteristic. Since a full tankfill is approximately 3,600 psig at 70° F., the vehicle tank could thenutilize direct fill.

Currently, in either a cascade fast-fill system or a buffered fast-fillsystem, a problem arises when multiple vehicles having differing tankpressures seek compressed gas from the same storage bank, or whenmultiple vehicles having differing tank pressures seek to be directlyfilled. For example, when two vehicles having differing tank pressuresseek compressed gas from the same storage bank, a vehicle having a lowertank pressure receives a greater percentage, if not 100 percent, of thecompressed gas than the vehicle having a higher tank pressure. This isbecause, without external influence, compressed gas flows from a regionof higher pressure to a region of lower pressure. As a result, whencompressed gas flows from the same storage bank to the vehicle having alower tank pressure, the flow of compressed gas to the vehicle having ahigher tank pressure can greatly decrease or even stop. Logically, theuser of the vehicle having a higher tank pressure may become frustratedthat, for at least a period of time, little or no compressed gas isbeing dispensed to the user's vehicle. This period of time can last froma few seconds to a few minutes.

Additional problems may result where little or no compressed gas isdispensed to a vehicle having a higher tank pressure. The user of avehicle having a higher tank pressure may prematurely terminate the fillby manually turning off or disconnecting from the dispenser, or thedispenser may automatically terminate the fill where little or nocompressed gas is conveyed to a vehicle having a higher tank pressure.Further, many compressed gas dispensers obtain data during the fill tocreate target fill pressures based on ambient temperature and the amountof gasoline gallon equivalents dispensed. By terminating the fill early,the dispenser loses these set points.

Even further, when a user attempts to top off the prior incomplete fill,the user is not usually able to obtain a complete fill. As an example,on a warm day, the dispenser dispenses compressed gas to the vehicleuntil the tank reaches approximately 4,000 psig. Over time, as thecompressed gas cools, the pressure of the compressed gas decreases tothe target pressure of 3,600 psig at 70° F. However, if the fill isterminated prematurely either by the user or by the dispenser, acomplete fill is difficult for a period of time thereafter, since thedispenser assumes the compressed gas within the vehicle tank is atambient temperature.

Therefore, there is a need for a compressed gas delivery system thateliminates or greatly decreases the period of time in which little or nocompressed gas is dispensed to a vehicle having a higher tank pressureto provide a continuous fueling experience.

SUMMARY OF THE INVENTION

The present invention overcomes the foregoing and other shortcomings anddrawbacks of known compressed gas delivery systems heretofore known forrefueling multiple vehicle tanks, when multiple vehicles havingdiffering tank pressures seek compressed gas from the same storage bankor when multiple vehicles having differing tank pressures seek to bedirectly filled. While the invention will be described in connectionwith certain embodiments, it will be understood that the invention isnot limited to these embodiments. On the contrary, the inventionincludes all alternatives, modifications, and equivalents as may beincluded within the spirit and scope of the present invention.

In one embodiment, a compressed gas delivery system includes a controlsystem and at least one compressor fluidly connected to the controlsystem. The compressor is configured to provide a compressed gas to thecontrol system. The compressed gas delivery system further includes oneor more backpressure apparatuses fluidly connected between the at leastone compressor and the control system that is configured to convey adirect fill portion and a storage fill portion of the compressed gas tothe control system.

The compressed gas delivery system further includes a storage bankarrangement configured to receive the storage fill portion through thecontrol system. The storage bank arrangement, in turn, is configured toconvey the storage fill portion to the control system for dispensinginto one or more vehicles during a dispensing operation. The compressedgas delivery system further includes at least one distributor fluidlyconnected to the control system downstream thereof. A bypass conduit isfluidly connected between the at least one compressor and thebackpressure apparatus that is configured to convey a bypass fillportion of the compressed gas to the at least one distributor. As usedherein, the terminology “bypass fill portion of compressed gas” isintended to describe that portion of the compressed gas that is neitherstored in any one of the storage banks, nor dispensed directly to one ormore vehicles through the priority panel or control system, but ratherthat portion of the compressed gas from the one or more compressors thatbypasses the control system or priority panel entirely, and is dispenseddirectly to one or more vehicles located at the dispensers. As usedherein, the terminology “non-bypass fill portion of compressed gas” isintended to describe that portion of compressed gas that is preventedfrom passing through the bypass conduit, but rather, that portion of thecompressed that flows through the backpressure apparatus as either adirect fill portion of compressed gas or a storage fill portion ofcompressed gas.

The compressed gas delivery system further includes one or more deliveryconduits. The at least one distributor is configured to convey at leastthe bypass fill portion of the compressed gas to at least one of the oneor more delivery conduits.

In some embodiments, the storage bank arrangement includes a low storagebank, a middle storage bank, and a high storage bank, each being fluidlyconnected to the control system, while in other embodiments the storagebank arrangement includes a single storage bank.

In some embodiments, the control system is configured to convey thestorage portion of the compressed gas from the high storage bank to atleast one of the one or more delivery conduits.

In some embodiments, the one or more delivery conduits include a lowstorage bank delivery conduit, a middle storage bank delivery conduit,and at least two high storage bank delivery conduits, each being fluidlyconnected to the control system. Other embodiments include a highstorage bank delivery conduit and a bypass conduit, each being fluidlyconnected to the control system. Further, other embodiments use anotherdelivery conduit, such as the middle bank storage conduit, to distributethe bypass fill portion.

In some embodiments, the compressed gas is natural gas, while in otherembodiments, the compressed gas is hydrogen.

In some embodiments, the backpressure apparatus creates a lower pressuregas region between the backpressure apparatus and the control system.

In some embodiments, the compressed gas delivery system may furtherinclude a coalescing filter fluidly connected between the backpressureapparatus and the control system.

A method of continuously conveying compressed gas to a plurality ofvehicles is also provided. The plurality of vehicles includes at least afirst vehicle having a higher tank pressure and a second vehicle havinga lower tank pressure that are simultaneously seeking compressed gasfrom the same storage bank. The method includes compressing gas using atleast one compressor and conveying the compressed gas from at least onecompressor to a backpressure apparatus. A bypass conduit is fluidlyconnected between the at least one compressor and the backpressureapparatus for diverting a bypass fill portion of the compressed gasthrough the bypass conduit. The method further includes conveying thebypass fill portion of the compressed gas to at least one of theplurality of vehicles.

The above and other objects and advantages of the present inventionshall be made apparent from the accompanying drawings and thedescription thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention and,together with a general description of the invention given above, andthe detailed description of the embodiments given below, serve toexplain the principles of the invention.

FIG. 1 is a schematic of a compressed gas delivery system according toan embodiment of the present invention;

FIG. 1A is an enlarged view of an embodiment of the encircled area 1A inFIG. 1, showing details of the distributor's fluid connection to thecompressed gas delivery system; and

FIG. 2 is a schematic of a compressed gas delivery system according toanother embodiment of the present invention.

FIG. 3 is a schematic of a compressed gas delivery system according toyet another embodiment of the present invention.

FIG. 4 is a schematic of a compressed gas delivery system according tostill yet another embodiment of the present invention.

FIG. 5 is a schematic of a compressed gas delivery system according tostill yet another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures, and to FIGS. 1-5 in particular, acompressed gas delivery system 10, 100, 200, 300, 400 is shown accordingto various embodiments of the present invention. The exemplarycompressed gas delivery system 10, 100, 200, 300, 400 is designed tocontinuously refuel multiple vehicle tanks, when multiple vehicleshaving differing tank pressures seek compressed gas from the samestorage bank 16 a-c (of which any of the compressors 12 a-c may bedirecting gas to) or when multiple vehicles having differing tankpressures seek to be directly filled from one or more compressors 12 a-cof the compressed gas delivery system 10, 100, 200, 300, 400.

As shown in FIG. 1, the compressed gas delivery system 10 may have avariety of components, including one or more compressors 12, such ascompressors 12 a-c, for compressing gas received from a gas source 14, astorage bank arrangement 16 comprising one or more storage banks 16 a-cfor storing the compressed gas, a control system 18 for directing theflow of compressed gas, a backpressure apparatus 20 for creating abackpressure of compressed gas between the backpressure apparatus 20 andthe compressors 12 a-c, a bypass conduit 22 for bypassing a bypass fillportion 24 a of compressed gas, a distributor 26 for receiving thebypass fill portion 24 a of compressed gas, and a plurality of deliveryconduits 28 for conveying the compressed gas to a plurality ofcompressed gas dispensers 30, for dispensing the compressed gas into oneor more vehicles (not shown) located at the compressed gas dispensers30. As described above, and as will be described in more detail below,the terminology “bypass fill portion of compressed gas” is intended todescribe that portion of the compressed gas from the compressors 12 a-cthat is neither stored in any one of the storage banks 16 a-c, nordispensed directly to one or more vehicles through the control system 18or priority panel, but rather that portion of the compressed gas fromthe compressors 12 a-c that bypasses the control system 18 or prioritypanel entirely, and is dispensed directly to one or more vehicleslocated at the compressed gas dispensers 30.

The gas source 14 provides gas to the compressed gas delivery system 10,100, 200, 300, 400 potentially at a variety of different pressures. Thecompressed gas delivery system 10, 100, 200, 300, 400 is suitable fordispensing a variety of gases. The gas to be compressed could be naturalgas, hydrogen, a gaseous vehicle fuel, or any other suitable gas.Considering a natural gas supply in particular, natural gas is typicallysupplied at a low pressure (less than 0.5 pounds per square inch gauge(psig)), a medium pressure (5-60 psig), or a high pressure (greater than100 psig). One or more gas dryers 32 may be provided to remove moisturefrom the gas prior to compression. The gas should be sufficiently driedto remove moisture prior to being compressed by the compressors 12 a-c.Alternatively, the gas could be sufficiently dried prior to beingsupplied to the compressed gas delivery system 10, 100, 200, 300, 400.This eliminates the need to include the gas dryers 32.

At least one compressor 12 is provided in the compressed gas deliverysystem 10, 100, 200, 300, 400 to compress the gas supplied by the gassource 14 to a desired pressure. FIGS. 1-5 show three compressors 12 a-coperating in parallel. However, any suitable number of compressors 12may be utilized. Storage capacity, number of compressors, and compressorsize are preferably balanced to ensure that compressed gas is availableduring the necessary time frames and to minimize the number of times thecompressors 12 a-c are turned on and off. The horsepower rating and thegas inlet pressure of compressors 12 a-c determine the gas's flow rate,measured in standard cubic feet per minute (scfm) or gasoline gallonequivalent per hour (gge/hr). Multiple compressors 12 a-c increase thecompression flow rate and create system redundancy. Typically,compressors 12 a-c compress the supplied gas to approximately 4,200 psigto fill a vehicle having a desired tank pressure of approximately 3,600psig at 70° F.

In the embodiment of the compressed gas delivery system 10, 200, 300shown in FIGS. 1, 3, and 4 respectively, the storage bank arrangement 16stores a storage fill portion 24 b of the compressed gas. As shown, thestorage bank arrangement 16 has multiple storage banks 16 a-c. Thecompressed gas delivery system 10, 200, 300 as shown in FIGS. 1, 3, and4, is designed as a cascade fast-fill system according to oneembodiment. Alternatively, the compressed gas delivery system 100, 400shown in FIGS. 2 and 5 is designed as a buffered fast-fill systemaccording to another embodiment. In this embodiment, as shown in FIGS. 2and 5, the storage bank arrangement 116 has a single storage bank 116 a.Typically, each of the storage banks 16 a-c, 116 a is filled toapproximately 4,200 psig. However, the pressure of storage banks 16 a-c,116 a is not limited to approximately 4,200 psig. One of ordinary skillin the art will appreciate that a range of suitable pressures for thecompressed gas delivery system 10, 100, 200, 300, 400 is possible foreach of the storage banks 16 a-c, 116 a.

The compressed gas delivery system 10, 200, 300 shown in FIGS. 1, 3, and4 utilizes a cascade fast-fill system having the storage bankarrangement 16 comprising the three storage banks 16 a, 16 b, 16 c;i.e., a high storage bank 16 a, a middle storage bank 16 b, and a lowstorage bank 16 c. However, there is no requirement that the storagebank arrangement 16 have three storage banks 16 a-c for a cascadefast-fill system. It may be preferable, instead, that the storage bankarrangement 16 have more or less storage banks depending on the storageand dispensing requirements of the compressed gas delivery system 10,200, 300. Further, each storage bank 16 a-c, 116 a may have one or morestorage tanks (not shown), depending on the required capability of thecompressed gas delivery system 10, 100, 200, 300, 400 for dispensingoperations.

In the cascade fast-fill system shown in FIGS. 1, 3, and 4, controlsystem 18 controls the sequential opening and closing of the multiplestorage banks, commonly referred to as the “low storage bank 16 c,”“middle storage bank 16 b,” and “high storage bank 16 a,” respectively,to obtain the preferred filled vehicle tank pressure. The control system18 uses actuated valves that control the flow of gas into a vehicle orinto the storage bank arrangement 16, with each storage bank 16 a-ccomprising at least one storage tank. These actuated valves aretypically electronically controlled or gas actuated, but a person ofordinary skill in the art will appreciate that other valves could beutilized.

In one embodiment, the control system 18 comprises a “priority panel” aswill be understood by those of ordinary skill in the art. Suitablecontrol systems 18 or priority panels for use in the present inventionare commercially available from J-W Energy (Addison, Tex.) and ANGIEnergy Systems (Janesville, Wis.), for example.

Depending on at least the pressure of the gas supplied by the gas source14, the vehicle's tank pressure at fill initialization, and the user'sdesired fill pressure, the vehicle tank may not need to utilize all ofthe storage banks 16 a-c or the direct fill. Also, the flow rate for thestorage fill portion 24 b is typically greater than the flow rate for adirect fill portion 24 c. The flow rate for the direct fill portion 24 cis limited at least by size of the compressors 12 a-c and the flow rateand size of the conduits in the compressed gas delivery system 10, 100,200, 300, 400. The flow rate for the storage fill portion 24 b islimited at least by the size of the conduits in the compressed gasdelivery system 10, 100, 200, 300, 400.

Referring now to FIGS. 1-5, and according to one aspect of the presentinvention, a backpressure apparatus 20 is fluidly connected between thecompressors 12 a-c and the control system 18 to create a region ofhigher gas pressure between the compressors 12 a-c and the backpressureapparatus 20, and a region of lower gas pressure between thebackpressure apparatus 20 and the control system 18. In one embodiment,the region of higher gas pressure is approximately 4,000 psig and theregion of lower gas pressure is approximately 2,000 psig. While notshown, there may be more than one backpressure apparatus 20 fluidlyconnected between the compressors 12 a-c and the control system 18.

A suitable backpressure apparatus 20 for use in the present invention isa backpressure regulator, such as a TesCom 54-2300 Series Back PressureRegulator, commercially available from TesCom (Austin, Tex.) or aSwagelok BSHN6-02-11-VVK back pressure regulator, commercially availablefrom Swagelok (Solon, Ohio). The backpressure apparatus 20 could also bea reducing adaptor, a mechanical valve, a positional valve, or any othersuitable device that creates the desired higher and lower gas pressureregions between the compressors 12 a-c and the control system 18. Thebackpressure apparatus 20 may be installed either inside or outside thecontrol system 18 or priority panel.

The creation of both the region of higher gas pressure and the region oflower gas pressure is beneficial. First, as will be described in greaterdetail below, the region of higher gas pressure can be used to divertthe bypass fill portion 24 a of compressed gas to a distributor 26located fluidly downstream of the control system 18, so that the bypassfill portion 24 a itself does not enter the control system 18. Secondly,the region of lower gas pressure aids in the separation of unwantedheavy hydrocarbons that can exist in the compressed gas. Using theJoule-Thomson effect, unwanted heavy hydrocarbons may be removed fromthe compressed gas supplied to the control system 18. In one embodiment,an optional filter 38 can be fluidly connected between the backpressureapparatus 20 and the control system 18 to remove unwanted heavyhydrocarbons prior to the compressed gas entering the control system 18.The optional filter 38 could be a coalescing filter, by way of example.One suitable optional filter 38 for use in the present invention is aParker J Series filter commercially available from Parker Hannifin(Oxford, Mich.). However, one of ordinary skill in the art willappreciate that other suitable filters could be utilized.

The bypass conduit 22 conveys compressed gas, i.e., the bypass fillportion 24 a, from the compressors 12 a-c to the distributor 26 (FIGS.1-3) or distributors 26 a-c (FIGS. 4 and 5), thereby bypassing thecontrol system 18 or priority panel. Specifically, as shown in FIGS.1-3, the outlet of the bypass conduit 22 is fluidly connected to asingle distributor 26. Alternatively, multiple distributors 26 a-c maybe utilized as shown in FIGS. 4 and 5, where each dispenser 30 a-c has acorresponding distributor 26 a-c. The inlet of the bypass conduit 22 isfluidly connected between the compressors 12 a-c and the backpressureapparatus 20. FIGS. 4 and 5 show distributors 26 a-c being separatefrom, and not contained within, dispensers 30 a-c, potentially below thedispenser in the “sump”. However, a person of ordinary skill in the artwill appreciate that distributors 26 a-c may be placed within thedispensers 30 a-c.

Additionally, a person of ordinary skill in the art will appreciate thatthe bypass conduit 22 may be made from a variety of materials and have avariety of diameters, depending on the particular application. Ifrequired by code or for safety reasons, a bypass shutoff 42 may beincorporated as part of the bypass conduit 22 prior to, or fluidlyupstream of, the distributor 26. This bypass shutoff 42 may be a valveor other suitable flow control device. As shown in FIGS. 1-3, a checkvalve 44 may be incorporated as part of the bypass conduit 22 prior to,or fluidly upstream of, the bypass shutoff 42 and the distributor 26.Alternatively, as shown in FIGS. 4 and 5, check valve 44 may beincorporated fluidly downstream of the bypass shutoff 42. Additionally,as shown in FIGS. 4 and 5, a needle valve 54 may be incorporateddownstream of the check valve 44.

Referring now to FIGS. 1-3, not all of the compressed gas conveyedthrough the bypass conduit 22 can pass through the distributor 26, sincethe distributor 26 is selectively chosen to limit the flow of compressedgas therethrough. This causes the pressure of the compressed gas at, orupstream of, the backpressure apparatus 20 to exceed the intended setpoint of the backpressure apparatus 20. In response thereto, thebackpressure apparatus 20 will allow the non-bypass fill portion 24 b-cof compressed gas to flow to the control system 18. This results in acontinuous flow of compressed gas to all vehicles during a dispensingoperation. The orifice of the at least one distributor 26 may be sizedappropriately to only allow a portion of the compressed gas generated bythe compressors 12 a-c, to pass therethrough, while maintaining asuitable backpressure upstream of the backpressure apparatus 20 so thatthe remaining gas, i.e., the non-bypass fill portion 24 b-c of thecompressed gas, will pass through the backpressure apparatus 20. Thenon-bypass fill portion 24 b-c of the compressed gas will flow throughthe high storage bank delivery conduits 28 c, 28 d when multiplevehicles are obtaining compressed gas from these respective deliveryconduits. The introduction of the bypass fill portion 24 a of compressedgas may be at any point between the control system 18 and the pluralityof compressed gas dispensers 30. For example, the bypass fill portion 24a of compressed gas may be introduced inside each dispenser 30 a-c ofthe plurality of compressed gas dispensers 30.

As shown in FIGS. 1-3, the distributor 26 is fluidly connected to thebypass conduit 22 and to a plurality of delivery conduits 28. Thedistributor 26 is designed to allow the bypass fill portion 24 a ofcompressed gas to bypass the control system 18 or priority panelentirely, and be dispensed directly to one or more vehicles from one ormore compressed gas dispensers 30.

The distributor 26 may comprise one or more adaptors, a milled manifoldblock having a plurality of fluid passageways formed therein, or anyother structure suitable to fluidly connect the bypass conduit 22 to theplurality of delivery conduits 28. The one or more adaptors could beT-shaped adaptor, a Y-shaped adaptor or any other suitable adaptor knownto those of ordinary skill in the art. The manifold block may be milledfrom steel or other suitable material, or alternatively, could be madefrom a variety of other manufacturing processes known to a person ofordinary skill in the art. The distributor 26 may be unitary piece or becomprised of many individual pieces. The distributor 26 may optionallyinclude an apparatus to fine tune the volume of the bypass fill portion24 a before entering the distributor 26, such as a needle valve (notshown). If desired, the distributor 26 can be heated to prevent freezingif the operating climate so requires. The distributor 26 may include oneor more reducing adaptors. A suitable reducing adaptor for use in thepresent invention is commercially available from Swagelok (Solon, Ohio),part number SS-400-6-2.

Referring now to FIGS. 1-3, check valves 50 a-b are used to preventcompressed gas from reentering the priority panel or control system 18from the distributor 26. Check valves 50 a-b allow the compressed gas toflow in only one direction, allowing the compressed gas to flow from thecontrol system 18 to the distributor 26, and to the pair of high storagebank delivery conduits 28 c-d. One suitable check valve 50 a-b for usein the present invention is commercially available from Swagelok (Solon,Ohio), part number SS-CHS4-1.

With continued reference to FIGS. 1 and 2, the plurality of deliveryconduits 28 are used to convey the compressed gas from the distributor26 to two or more compressed gas dispensers 30 a-b located fluidlydownstream of the priority panel or control system 18. The deliveryconduits 28 are typically sized to maximize the flow of the compressors12 a-c, even if only a single vehicle seeks compressed gas. As shown inFIG. 1, the compressed gas delivery system 10, according to anotheraspect of the present invention, has a low storage bank delivery conduit28 a, a middle storage bank delivery conduit 28 b, and two high storagebank delivery conduits 28 c or 28 d, each being fluidly connected to thecontrol system 18 or priority panel and to the compressed gas dispensers30 a-b. In this embodiment, each of the plurality of compressed gasdispensers 30 a-b is fluidly connected to a separate high storage bankdelivery conduit 28 c or 28 d, respectively, so that if three compressedgas dispensers were provided, for example, three high storage bankdelivery conduits would be utilized. Likewise, if four compressed gasdispensers 30 were provided, four high storage bank delivery conduitswould be utilized, and so on. The compressed gas dispensers 30 a-b areconfigured to convey compressed gas to a pair of vehicles (not shown)located at the pair of compressed gas dispensers 30 a-b.

FIGS. 1 and 2 show two compressed gas dispensers 30 a-b, FIG. 3 shows asingle compressed gas dispenser 30, and FIGS. 4 and 5 show threecompressed gas dispensers 30 a-c. In FIGS. 1 and 2, each compressed gasdispenser 30 a-b can provide compressed gas to one or more vehicles (notshown). FIG. 3 shows a single compressed gas dispenser 30 that canprovide compressed gas to one or more vehicles (not shown) at a timeduring a dispensing operation using one or more delivery hoses (notshown). In another embodiment, the bypass fill portion 24 a may beconveyed to a single compressed gas dispenser 30 a. As shown in FIG. 3,the bypass conduit 22 is fluidly connected to the compressed gasdispenser 30 and the distributor 26, both of which can be located withinthe compressed gas dispenser 30. If required by code or for safetyreasons, a bypass shutoff 42 may be incorporated as part of the bypassconduit 22 prior to, or fluidly upstream of, the distributor 26. Also, acheck valve 44 may be incorporated as part of the bypass conduit 22prior to, or fluidly upstream of, the bypass shutoff 42 and thedistributor 26.

Alternatively, as shown in FIGS. 4 and 5, a single high bank deliveryconduit 28 c may extend from the control system 18 to the compressed gasdispensers 30 a-c. As shown, each of the compressed gas dispensers 30a-c, contain separate distributors 26 a-c fluidly connected to thebypass conduit 22 for conveying the bypass portion 24 a of thecompressed gas. Additionally, a single bypass conduit 22 is positionedbetween the control system 18 and the plurality of dispensers 30. Thedistributors 26 a-c may be positioned in the space below each dispenser30 a-c (known as the “sump”). This arrangement allows distributors 26a-c to provide the bypass fill portion 24 a to dispenser 30 a-c, each ofwhich may have one or more hoses (not shown) connected thereto.

While not shown in FIG. 4, the bypass fill portion 24 a may be conveyedthrough the middle storage bank delivery conduit 28 b to reduce thenumber of conduits connecting to the compressed gas dispensers 30 a-c.For example, if two vehicles seek compressed gas simultaneously, onevehicle could obtain the storage fill portion 24 b using the highstorage bank delivery conduit 28 c while the other vehicle may obtainthe bypass fill portion 24 a using another delivery conduit 28, such as,for example, the middle storage bank delivery conduit 28 b. This allowsthe compressed gas delivery system 300 to be retrofitted on currentsystems without having to add an additional bypass conduit 22. Anadditional check valve would be incorporated into the middle storagebank delivery conduit, downstream of the control system 18 and upstreamof the bypass conduit 22 merging with the middle storage bank deliveryconduit 28 b. Likewise, check valves and distributors 26 a-c would beincorporated downstream on, or near, each dispenser 30 a-c of theplurality of dispensers 30.

While the compressed gas flow rate in the bypass conduit 22 will changesignificantly throughout the various stages of a multiple vehicle fill,the bypass conduit 22 conveys gas to a vehicle having a higher tankpressure than other vehicle(s) on the same bank enabling continuous flowto multiple vehicles as long as the inlet of the bypass conduit 22 has ahigher pressure than the pressure of the vehicle having a higher tankpressure.

In one embodiment, FIG. 1A shows a detailed schematic of the distributor26 and how the distributor 26 is fluidly connected to the compressed gasdelivery system 10, 100. One suitable bypass conduit 22 for use in thepresent invention is a 0.25 inch outer diameter stainless steel tubingcommercially available from Swagelok (Solon, Ohio), part numberSS-T4-S-049-20. A T-shaped adaptor comprising part of the distributor26, splits the 0.25 inch diameter bypass conduit 22 into two 0.125 inchouter diameter split bypass conduits 22 a-b. One suitable T-shapedadaptor suitable for use in the present invention is commerciallyavailable from Swagelok (Solon, Ohio), part number SS-400-3.

In this embodiment, one suitable conduit for use in the presentinvention as the split bypass conduits 22 a-b, could be 0.125 inch outerdiameter conduit commercially available from Swagelok (Solon, Ohio),part number SS-T2-S-028-20. The split bypass conduits 22 a-b create asuitable backpressure upstream of the backpressure apparatus 20, so asto only allow a portion of the compressed gas created by the compressors12 a-c to be conveyed therethrough. This enables the remainder ofcompressed gas, i.e., the non-bypass fill portion 24 b-c, to flowthrough the backpressure apparatus 20 and to the control system 18. Inthis embodiment, the split bypass conduit 22 a could be a 0.125 inchouter diameter conduit that is fluidly connected to the control system18 and to a first high storage bank delivery conduit 28 c. In thisembodiment, the split bypass conduit 22 b could be a 0.125 inch outerdiameter conduit that is fluidly connected to the control system 18 andto the second high storage bank delivery conduit 28 d. A person ofordinary skill in the art will understand a range of conduit outerdiameters may be utilized based on the requirements of the compressedgas delivery system 10, 100, 200, 300, 400 application. Suitableadaptors (not shown) are provided to fluidly connect the pair of splitbypass conduits 22 a-b, which may each have a 0.125 inch outer diameter,to the pair of first and second high storage bank delivery conduits 28c-d, respectively, which may each have a 1.0 inch outer diameter.

In one embodiment, compressors 12 a-c compress the gas supplied from thegas source 14 at approximately 500 standard cubic feet per minute(scfm). The backpressure apparatus 20 creates the region of higherpressure between the compressors 12 a-c and the backpressure apparatus20, prior to the downstream control system 18. This allows the bypassfill portion 24 a of the compressed gas to bypass the normal operationof the control system 18 or priority panel, and based on the sizing ofthe conduits used, continuously flow a portion of the 500 scfm to avehicle having a higher tank pressure. During direct fill, thecompressors 12 a-c operate with the backpressure apparatus 20 create abackpressure between the compressors 12 a-c and the backpressureapparatus 20.

Exemplary flow calculations can be seen in Table 1. One suitable splitbypass conduit 22 a-b for use in the present invention could be 0.125inch diameter conduit commercially available from Swagelok (Solon,Ohio), part number SS-T2-S-028-20 having a tube outer diameter of 0.125inches, a tube inner diameter of 0.069 inches, a tube wall of 0.028inches, a weight of 0.029 pounds per foot, and a working pressure of8,500 psig. For these exemplary flow calculations, the distributor 26has an inner diameter of 0.069 inches.

In an exemplary embodiment, assume that two vehicles, vehicle A andvehicle B, located at the compressed gas dispensers 30 a-b, seekcompressed gas from the high storage bank 16 a, while the compressors 12a-c are operating. With current compressed gas systems, most, if notall, of the compressed gas from the high storage bank delivery conduit28 c-d would be dispensed to the vehicle having the lower tank pressure.However, with the use of the backpressure apparatus 20, the distributor26, and the operation of compressors 12 a-c, a suitable backpressure iscreated that can supply the bypass conduit 22 with the bypass fillportion 24 a of compressed gas, while allowing the non-bypass fillportion 24 b-c of compressed gas to flow through the backpressureapparatus 20 and to the control system 18.

In this two vehicle exemplary embodiment, a portion of the bypass fillportion 24 a of the compressed gas flows to the vehicle having a highertank pressure, while the other portion of the bypass fill portion 24 aof the compressed gas flows to the vehicle having the lower tankpressure. The non-bypass fill portion 24 b-c of compressed gas, whichcould not be conveyed through the distributor 26, is conveyed throughthe backpressure apparatus 20 and flows to the vehicle having a lowertank pressure. While the compressed gas flows may not necessarily beevenly split, multiple vehicles could obtain compressed gas regardlessof their vehicle tank pressures to achieve a full tank fill of 3,600psig at 70° F. and maintain the temperature compensated set points ofthe compressed gas dispensers 30. This allows for a continuous fuelingexperience for both vehicles.

Considering this exemplary embodiment and referring to Table 1 inparticular, assume compressors 12 a-c compress gas at a rate of 500scfm. Further assume that the backpressure apparatus 20 is set to atarget pressure of 4,000 psig. Vehicle A has a vehicle tank pressure of3,000 psig, resulting in a 1,000 psig pressure differential between thetarget pressure of 4,000 psig and vehicle A's tank pressure of 3,000psig. Vehicle B has a vehicle tank pressure of 2,400 psig, resulting ina 1,600 psig pressure differential between the target pressure of 4,000psig and vehicle B's tank pressure of 2,400 psig. Using Table 1, thiswould allow vehicle A, having a 1,000 psig pressure differential, toreceive 102 scfm of the bypass fill portion 24 a of compressed gas.Further using Table 1, this would allow vehicle B to receive 121 scfm ofthe bypass fill portion 24 a of compressed gas and 277 scfm of thenon-bypass fill portion 24 b-c of compressed gas. This exemplaryembodiment would allow vehicle A to receive 102 scfm of compressed gasand vehicle B to receive 398 scfm of compressed gas. One of ordinaryskill in the art will appreciate that different flow rates could occurat various times during the fill, and this exemplary embodiment providesa snapshot of the compressed gas delivery system 10, 100, 200 at asingle point in time.

While the present invention has been illustrated by description ofvarious embodiments and while those embodiments have been described inconsiderable detail, it is not the intention of applicant to restrict orin any way limit the scope of the appended claims to such details.Additional advantages and modifications will readily appear to thoseskilled in the art. The invention in its broader aspects is thereforenot limited to the specific details and illustrative examples shown anddescribed. Accordingly, departures may be made from such details withoutdeparting from the spirit or scope of Applicants' invention.

TABLE 1 Exemplary Flow Calculations Bypass Fill 1 49 68 82 93 102 109116 121 Portion Flow Rate Estimation (SCFM) Viscosity 0.018 0.018 0.0180.018 0.018 0.018 0.018 0.018 0.018 Temperature 70 70 70 70 70 70 70 7070 (° F.) Gas Molecular 19.5 19.5 19.5 19.5 19.5 19.5 19.5 19.5 19.5Weight Specific Heat 1.27 1.27 1.27 1.27 1.27 1.27 1.27 1.27 1.27 RatioCompressibility 1 1 1 1 1 1 1 1 1 Factor Inlet Pressure 4000 4000 40004000 4000 4000 4000 4000 4000 (PSIG) Pipe Length 1 1 1 1 1 1 1 1 1(Feet) Pressure 0 200 400 600 800 1000 1200 1400 1600 DifferentialTarget (PSIG) Pressure loss 0.103 198.964 396.962 599.225 801.0941002.894 1190.001 1413.34 1604.253 (PSIG) Overall K 9.747 9.398 9.3969.395 9.394 9.394 9.394 9.393 9.393 K1 235677.137 93.175 46.568 30.98323.405 18.973 16.275 14.064 12.721 K2 235667.389 83.777 37.172 21.58814.011 9.579 6.881 4.67 3.328 Inlet Mach 0.002 0.09 0.124 0.15 0.170.186 0.199 0.212 0.221 Number Outlet Mach 0.002 0.094 0.138 0.176 0.2120.249 0.283 0.327 0.368 Number Reynolds 15675 768058 1065877 12853221457743 1598815 1708538 1818261 1896634 Number Flow Region TurbulentTurbulent Turbulent Turbulent Turbulent Turbulent Turbulent TurbulentTurbulent Fluid Velocity 2.395 117.37 162.88 196.415 222.763 244.321261.088 277.855 289.831 (ft/sec) Density at Inlet 13.766 13.766 13.76613.766 13.766 13.766 13.766 13.766 13.766 Specific Vol. at 0.073 0.0730.073 0.073 0.073 0.073 0.073 0.073 0.073 Inlet

What is claimed is:
 1. A compressed gas delivery system, comprising: acontrol system; at least one compressor fluidly connected to the controlsystem and being configured to provide a compressed gas to the controlsystem, a backpressure apparatus fluidly connected between the at leastone compressor and the control system, wherein the backpressureapparatus is configured to convey a direct fill portion and a storagefill portion of the compressed gas to the control system; a storage bankarrangement configured to receive the storage fill portion from thecontrol system and being configured to convey the storage fill portionto the control system; at least one distributor fluidly connected to thecontrol system; a bypass conduit fluidly connected between the at leastone compressor and the backpressure apparatus, wherein the bypassconduit is configured to convey a bypass fill portion of the compressedgas to the at least one distributor; and one or more delivery conduits,wherein the at least one distributor is configured to convey at leastthe bypass fill portion of the compressed gas to at least one of the oneor more delivery conduits.
 2. The compressed gas delivery system ofclaim 1, wherein the storage bank arrangement comprises a low storagebank, a middle storage bank, and a high storage bank, each being fluidlyconnected to the control system.
 3. The compressed gas delivery systemof claim 2, wherein the control system is configured to convey thestorage fill portion of the compressed gas from the high storage bank toat least one of the one or more delivery conduits.
 4. The compressed gasdelivery system of claim 2, wherein the one or more delivery conduitsfurther comprise a low storage bank delivery conduit, a middle storagebank delivery conduit, and at least two high storage bank deliveryconduits, each being fluidly connected to the control system.
 5. Thecompressed gas delivery system of claim 2, wherein the one or moredelivery conduits further comprise two high storage bank deliveryconduits each being fluidly connected to the control system.
 6. Thecompressed gas delivery system of claim 1, wherein the compressed gas isnatural gas.
 7. The compressed gas delivery system of claim 1, whereinthe compressed gas is hydrogen.
 8. The compressed gas delivery system ofclaim 1, wherein the backpressure apparatus creates a low pressure gasregion between the backpressure apparatus and the control system.
 9. Thecompressed gas delivery system of claim 1, further comprising acoalescing filter fluidly connected between the backpressure apparatusand the control system.
 10. The compressed gas delivery system of claim2, wherein the one or more delivery conduits further comprise a singlehigh storage bank delivery conduit and the bypass conduit.
 11. A methodof continuously conveying compressed gas to a plurality of vehicles,wherein the plurality of vehicles includes at least a first vehiclehaving a higher tank pressure and a second vehicle having a lower tankpressure that are simultaneously seeking compressed gas from the samestorage bank, the method comprising: compressing gas using at least onecompressor; conveying compressed gas from the at least one compressor toa backpressure apparatus; fluidly connecting a bypass conduit betweenthe at least one compressor and the backpressure apparatus; diverting abypass fill portion of the compressed gas through the bypass conduit;and conveying the bypass fill portion of the compressed gas to at leastone of the plurality of vehicles.
 12. A compressed gas delivery system,comprising: a control system; at least one compressor fluidly connectedto the control system and being configured to provide a compressed gasto the control system, a backpressure apparatus fluidly connectedbetween the at least one compressor and the control system, wherein thebackpressure apparatus is configured to convey a direct fill portion anda storage fill portion of the compressed gas to the control system; astorage bank arrangement configured to receive the storage fill portionfrom the control system and being configured to convey the storage fillportion to the control system; at least one distributor fluidlyconnected to the control system; a bypass conduit fluidly connectedbetween the at least one compressor and the backpressure apparatus,wherein the bypass conduit is configured to convey a bypass fill portionof the compressed gas to the at least one distributor; and one or moredelivery conduits, wherein the at least one distributor is configured toconvey the bypass fill portion of the compressed gas to at least one ofthe one or more delivery conduits, and wherein a non-bypass fill portionof the compressed gas passes through the backpressure apparatus aseither the direct fill portion, the storage fill portion, or acombination thereof.